Experimental investigation on steam flow condensation in the presence of noncondensable gas inside horizontal multi-head spiral channels

Abstract

An experimental investigation on the heat transfer characteristics of steam flow condensation inside the horizontal circular channel and the horizontal multi-head spiral channels is performed. The effects of the pressure, the water flow rate and the noncondensable gas mass fraction on the flow condensation performance are investigated. Two sets of experimental test sections are established: one is horizontal circular channel (HCC) consisting of an inner condenser tube and an outer cooling jacket, and the other is the horizontal multi-head spiral channels (HMHSC) with a multi-head spiral groove bar in the condenser tube mentioned above. The hot steam flows inside the inner condenser tube and the cooling water flows inside the annular channel in a counterflow direction. The mass flow rate and the local temperature are measured to acquire the average condensation heat transfer coefficient and the condensate mass flow rate. The experimental results indicate that the heat transfer performance of steam flow condensation in the HMHSC is better than that in the HCC under the same condition, and the average enhancement factor of the HMHSC compared against the HCC is about 2.35 times for the average condensation heat transfer coefficient, and 1.25 times for the condensate mass flow rate. Similarly, the average steam-side pressure loss of the HMHSC model is about 1.27 times higher than that of the HCC model under the same experimental conditions. It is obvious that the HMHSC can effectively enhance the heat transfer, while the average steam-side pressure loss will increase correspondingly.